Transcript 11.5 & 11.9-Electrical Energy Sources

12.1 Renewable and Non-Renewable
Energy Resources for Generating
Current Electricity
p. 474-489
Producing Large Amounts of
Electrical Energy…

Renewable resources
◦ Best to use since they constantly
replenish themselves
◦ However, don’t satisfy all of our energy
needs
◦ Ex: hydroelectric, tidal generation,
biomass thermal generation, geothermal
generation, wind energy, solar energy
Non-renewable resources
◦ Most of our energy comes from these
sources (89%)
◦ These can’t be replenished in a reasonable
amount of time
◦ Ex. burning fossil fuels, nuclear power
(radioactive materials)
Ways to Produce Electrical Energy
1.



Hydroelectric
generating stations
Falling water turns
water turbine wheels
Turbine turns a
generator, producing
electrical energy
Ex. Niagara Falls
How Hydroelectric Power Works

http://www.opg.com/power/hydro/howitw
orks.asp
USING HEAT TO
GENERATE ELECTRICITY
Make steam to turn the turbine….
 Thermal generation uses heating water to
produce steam to rotate a turbine
 3 ways to generate steam:
(i) burning of plant/animal materials (biomass
and burning of fossil fuels)
(ii) using radioactive materials (nuclear
power)
(iii) geothermal energy from the Earth’s
deep crust

Burning of Fossil


Burning fossil fuels
(coal, oil, and natural
gas)- animal and plant
matter decayed over
millions years
All of these produce air
pollution, smog and acid
precipitation
Biomass: any form of plant or animal
matter (including wood, straw, manure, plantbased oils and decaying natural materials)
 This material can be burned as fuel
(biodegradable wastes found in sewage gas
and landfill gas)
 Methane gas released when plant and animal
matter decays can be collected and burned
as fuel


Biomass (biofuel) is renewable because the
plant and animal waste is replenished

**Fossil fuels have been transformed over
long periods of time and are not
considered biomass
(Nuclear Power:
Using Radioactive Materials in
Thermal Generation
Long tubes (feeder rods) filled with
radioactive uranium and placed in a reactor
 Neutrons collide with the uranium in a high
energy reaction
 nuclear fission occurs breaking the uranium
atoms apart
 huge amounts of energy is released

How Nuclear Power Works
http://www.howstuffworks.com/nuclearpower.htm
 http://www.opg.com/power/nuclear/howit
works.asp

Geothermal Energy
 Thermal
energy from
deep in Earth’s crust
in hot springs and
geysers creates
steam
Solar Panels
 Photovoltaic
cell
converts light into
electrical energy
 Light from the sun
is captured and
creates a flow of
electrons to create
electrical energy

Wind turbines
 The.
force of the
wind is used to
spin many small
turbines to
produce energy
Tidal Generation
Newer method
 Movement of tides
used to rotate a
water turbine
 Two generation
cycles a day because
twice a day tide goes
in and out

Environmental Concerns
produce electrical energy without harming
the environment
 For example, burning of fossil fuels
produces carbon dioxide which
contributes to problem of global
warming
 Want to maintain sustainability-consider the
social, economic, and environmental aspects
of the production and use of electrical energy
now and in the future

Homework:
Read 12.1
copy/summarize table 12.1 on pages 482483
Complete p. 479 #1-5, p. 483 #1-5